Here is a video of the 12 week scan.   The movement you see is not the baby moving but the nurse moving the scanner around to look at different parts of  the  baby.   

You  might  be  able  to  see a heartbeat.   It's quite clear on the original but  we  had  to 
reduce  the  image  quality  to  keep  the  download time  reasonable for dial-up connections.  

Note - Windows Media Player is required to see this video.